An Orthogonal Frequency Division Multiplexing (OFDM) wireless communication system divides a frequency band into subchannels and transmits data on the subchannels at the same time.
The OFDM wireless communication system classifies the subchannel composition to a band selection subchannel and a diversity subchannel.
The band selection subchannel includes adjacent subcarriers and, thus, has a similar channel condition. Correspondingly, terminals can maximize a transmission capacity by adopting an adaptive modulation and coding suitable for the band selection subchannels.
The diversity subchannel distributes its subcarriers over the entire frequency band to acquire a frequency diversity gain.
As stated above, the wireless communication system composes the band selection subchannel with the adjacent subcarriers of the similar channel condition, and the diversity subchannel with the subcarriers spread over the entire frequency band. The band selection subchannel and the diversity subchannel are used in the different environments.
What is needed is a method for composing the band selection subchannel and the diversity subchannel to be used according to the channel condition in the wireless communication system.